Permutation switch with a pair of bus bars each having spaced apart integral spring fingers



June 29, 1965 R. w. DAVIDSON 3,192,331

PERMUTATION SWITCH WITH A PAIR OF BUS BARS EACH HAVING SPACED APARTINTEGRAL SPRING FINGERS Filed Sept. 27, 1961 RAYMOND W. DAVIDSONINVENTOR.

ATTY

United States Patent Oregon Filed Sept. 27, 1961, Ser. No. 141,691 2Claims. (Cl. 200-43) This invention relates to improvements inpermutation switches of the general type shown and described in myUnited States Letters Patent No. 2,984,717. The general object of thepresent invention is to improve upon the type of switch shown in thatpatent wherein a plurality of disc-like tumblers arranged for freeselective rotation about a tubular fixed shaft mounted in one end of acase, are provided with segmental peripheries consisting in respectiveconductor and insulator segments, and are arranged for engagement ofsaid peripheries by a plurality of contact brushes which are mounted onthe inside of and insulated from the lateral wall of the case andproject radially inwardly into contact with the tubular peripheries.

The principal objects of the present invention are to provide animproved and simplified construction of tumbler actuating andinter-engaging means; an improved and simplified construction andarrangement of contact brushes, adjustable and settable meansinterconnecting the tumbler supporting shaft and actuating meanstherefor, and similar means interconnecting the tumbler shaft withtumbler pick-up means whereby the various combinations that can beassigned to the switch are of greater magnitude than any other that I amaware of.

The foregoing and other objects and advantages which will becomesubsequently apparent reside in the details of construction andoperation as more fully hereinafter described and claimed, referencebeing had to the accompanying drawing forming a part hereof, whereinlike numerals refer to like parts throughout the several views, and inwhich:

FIGURE 1 is a front elevational view of a permutation switch made inaccordance with my invention.

FIGURE 2 is a side elevational view of FIGURE 1 with a fragment brokenaway for convenience of illustration and showing in broken linesmounting means for the switch.

FIGURE 3 is a view of the right hand side of FIGURE 2 on an enlargedscale and with the mounting flange removed.

FIGURE 4 is an axial sectional view of FIGURE 2 on an enlarged scalewith fragments of the tumblers therein broken away.

FIGURE 5 is a perspective detail view of a pair of bus bars and brushcontacts integrated therewith.

FIGURES 6 and 7 are front and side elevational views respectively of atypical tumbler.

FIGURE 8 is a side elevational view of a modified form of the inventionand mounting means therefor with fragments broken away for convenienceof illustration, and

FIGURE 9 is a sectional detail view on an enlarged scale takenapproximately along the line 9-'9 of FIGURE 8;

With continuing reference to the drawing, reference numeral 1 indicatesgenerally a casing having a cylindrical lateral wall 2, an integratedclosure wall 3 and mounting flange 4 as its forward end, and a removabledisc 5 closing the rearward end. The disc is provided with diametricallyopposed apertures 6 and an upwardly opening recess 7. Similarly opposedinternally threaded bosses 3 are integrated with the interior wall ofthe casing.

By this arrangement, as best illustrated in 'FIGURE 2, the switch may bemounted to a wall 10 or similar support by extending the casing 1through an opening 11 in the wall and abutting the mounting flange 4against the outside of the wall. The switch is secured to the wall bymeans of a generally U-shaped bracket 13 through whose cross member 14studs 15 extend and threadedly engage the internally threaded bosses 8.Lock nuts 16 and 17 are applied to the studs on the inside and outsideof the bracket cross member 14, and the feet 24 of the bracket aresecured to the inside of the wall '10 by screws 21.

lournalled as at 24 in the front closure wall 3 of casing 1 is a roundtumbler-supporting shaft 25 (see FIG. 4) of square section at itsfor-ward and rearward ends as at 26 and 27 respectively. A dialing knob28, removably secured as at 29 to the front end of the shaft, has itsflange 3% (FIG. 1) inscribed with numbered indicator marks as shown,cooperable with .a fixed indicator mark or reference point 31 on the rimof the mounting flange 4.

Rotatably mounted upon the shaft 25 are a series of identical tumblers35, 36, 37 and 38 maintained on the shaft by an actuator arm til on thesquared inner end 27 thereof and a cotter pin 41 extending through thatend of the shaft. Each tumbler is generally in the form of a flatcircular disc having a central opening 42 therethrough for rotatablemounting on shaft 25, and a forwardly opening annular recess 43 thereinwith a radially disposed driving web across the recess as at 45. Theopposite or rearward side of each tumbler dis-c is provided with adriving pin 50, and the rim of each disc is provided with adjoiningV-notches 52 to define between them respective transverse ridges oftriangular section as shown in FIGURES 3 and 6.

Each tumbler is made of metal or other conductive material such, forexample, as that used in die casting and its rim is provided with agroove 55 undercut on both of its sides as shown to receive by a forcedfit a segment 56 of dielectric material provided on its exterior withtransverse V-notches 57 matching in shape and continuity the V-notches52 in the rim of the tumbler. The inner or bottom surface of eachsegment '56 (FIG. 3) is provided with a nodule 56A for similarengagement with a receiving recess 5613 in the bottom wall of the grooveto thus securely mount the segment within the respective groove 55.

A semi-cylindrical mounting plate 60 of dielectric material, such assynthetic resin plastic, having a chordal inner face 61 to providestrengthening thickness thereacross, is injection molded to fit snuglywithin the arcuate space defined between the circumferentially spacedbosses 8 with the side edges of the mounting plate bearing against thebosses, as shown.T he mounting plate is secured in place by securementof the closure disc 5 to the bosses 8 by means of the studs 15.

Two bus-bars 65 and 66 (FIG. 5) disposed one above the other withinsulation 67 therebetween (FIG. 4) are of flat formation throughouttheir length and integrated with outwardly extending spring contactfingers 6S and 69 respectively curved downwardly on unlike radii ofcurvature, as best shown in FIGURE 5, before assembly with the tumblerswithin the casing 1, terminating in tip ends of angular formation on acommon horizontal plane and matching the angularity of the V-notches 52and 57 for positive engagement therewith after assembly with thetumblers to elfect initial resistance in said spring fingers againstunintentional rotation of the tumblers in either direction. Theresistance of the spring fingers re-aots through the mounting plate andthe sides thereof against the bosses 8. It will be plainly seen inFIGURE 3 that the reach of the spring fingers 6869 in both series, whenin tension, resulting from such assembly, assume a positionsubstantially tangential to the peripheral surfaces of the tumblers35438. This makes possible the utilization of a r 66 is of the samematerial as the mounting plate 6% and in securing both bus-bars to eachother and to the mounting plate it is merely necessary to apply a hotiron to weld the components into an integral assembly or the contiguoussurfaces thereof could be coated with suitable adhesive. The conductors72 and 73 extend outwardly through the recess 7 in the disc and are inclosed circuit with a source (not shown) of electrical current and forexample an electrical lock-actuating mechanism (not shown) such as asolenoid and core, or the like, wherein the core is adapted to functionas a locking bolt when the solenoid is energized. The conductors couldalso be in circuit with an alarm through conductor tape, such as is usedon jewelry store windows, vaults, safes and the like, in burglar alarmsystems wherein when the circuit is broken the alarm is energized.

The bus-bars '65 and 66 are installed as aforesaid and in such mannerthat their angular tips are at all times spring-urged into firm,non-slipping but removable engagement with the V-notches of theirrespective tumbler discs 35-38. From the foregoing it will be readilyapparent that an electrical circuit through the bus-bars will remainclosed as long as any two of the contact fingers 68-69 are in contactwith their respective tumbler and that the circuit can only be brokenwhen all the contact fingers are in contact with the dielectric segments56 of their respective tumblers. Such making and breaking the electricalcircuit can only be accomplished by rotating the tumblers relative toeach other about their supporting shaft by means of the dialing knob 2-8and then only by an authorized person who has knowledge of the number ofturns to the right or left thereof to bring the various numberedindicator marks on the dial flange into registry with the fixedindicator mark 31 on the rim of the flange 4.

In the initial rotation of the knob 28 and actuator arm they will berotated several revolutions, so as to cause the driving pins 59 ofsuccessive tumblers, beginning with tumbler 38, to inter-engage withdriving webs of adjacent tumblers so that the successive tumblers willin turn be. picked up and rotated along with tumbler 38. The first stopat the indicator markGl will result in the dielectric segment 56 of thefirst tumbler 35 being brought into engagement with its respectivecontact fingers 68 and 69 of the bus-bars 65 and 66 thus initiallybreaking the circuit only through those two contact fingers.

With the first tumbler 35 now held against rotation by the angular tipsof the contact fingers in engagement with the matching V-notches in thedielectric segment, the dialing knob 28 is rotated in the oppositedirection, one turn less than previously, causing actuator arm 46 tofirst dis engage from one side of driving pin 59' of the fourth orforemost tumbler 38 and rotate around into engagement with the otherside of said pin causing driving web of tumbler 38 to pick up pin of thethird tumbler 37 to rotate the same in said opposite direction. Web -45of tumbler 37 will pick up pin 50 of the second tumbler 36 to rotate thesame until its dielectric segment 56 is engaged by the tips of itsrespective contact fingers and so held against further rotation. Withthe tumblers 35 and 36 now in the positions just mentioned, the circuithas been successively broken through their respective contact fingers.Rotation of the dialing knob 28 and actuator arm 40 in an oppositedirection will similarly impart rotation to the third tumbler 37 toposition its dielectric segment and respective contact fingers incircuit-open position.

Rotation of dialing knob and actuator arm in a reverse direction willfinally position the 'dielectric segment of the rearmost tumbler 33 incircuit-open engagement with its respective contact fingers and thuscompletely break the circuit through the bus-bars 65 and 66 and theconductors 72 and 73 leading therefrom. V

. All of the dialing operations just described, to be eiiective, must bedone in accordance with the numerical combinations assigned to theswitch in its entirety, and such combinations can be quickly andconveniently varied by rota-tably resetting the actuator arm 40 anddialing knob on their respective squared ends of the tumbler-supportingshaft 25. a a

In the modified form of the. invention shown in FIGURE 8, the numericalcombinations can be varied to an even'greater extent because of theconfiguration of the knob-end ZdA-of tumbler-supporting shaft 25A whichmay be that as shown, or of hexagonal, octagonal or any othermulti-faced or non-circular section and fitted within and secured, as at75, to one end of a matching coupling 76 whose opposite end is of squaresection for securement as at '77 to the dialing knob 28A.

In this modification the switch in its entirety is shown secured to asupport which, for example, could be the front wall of a drawer of afiling cabinet or similar storage receptacle wherein said supportcomprises a heavy steel main wall 80 and inner andouter walls 81 and 82.The studs 15A extend through the inner wall 81 and into threadedsecurement with drilled and tapped holes 84 in the main wall 80.Similarly the mounting flange 4A of the closure wall 3A is secured tothe outerwall 52 and main wall 80 by screws 85. p From the foregoing itwill be apparent that I have provided a permutation switch which is ofgreatly simplified and improved construction containing a minimum numberof parts to obtain optimum results and wherein such simplifiedconstruction essentially includes, the unitary tumbler supporting means,the novel dielectric segments and their mounting in the tumblers, thenovel bus-bar assembly and contactfingers integrated therewith, and thenovel formation of the ends of the tumbler-supporting shaft and matchingopenings in the actuator arm and dialing knob for varying numericalcombinations assigned to the switch to a greater magnitude than in anycomparable device that I am aware of.

While Lhave shown and described particular forms of embodiment of myinvention, I am aware that many minor changes therein will suggestthemselves to others skilled in the art without departing from thespirit and scope of the invention Having thus described my invention,what I claim as new and desire'to protect by Letters Patent is:

1. In a permutation switch including ahollow cylindrical casing closedatboth of its ends having a plurality of cylindrical tumblers rotatablymounted therein which have conducting and non-conducting surfaceportions, electrical conductors extending to the interior of thehousing, and a semi-cylindrical mounting plate supported within thecasing and having a relatively thick chordal inner face, the improvementcomprising. I

a pair of bus bars of flat formation throughout their length secured toand spaced from each other by a dielectric bonding material throughoutthe major portion of their length and divided outwardly beyond one endof said bond into two conductive terminals electrically connected tosaid conductors;

both bus bars being bonded as a unit throughout their said major portionto said chordal inner face of said mounting plate; a

each of said bus bars having laterally, outwardly extending, spacedapart integral spring contact fingers curved downwardly, the fingers ofone of said bars straddling those of the other of said bars to provide aseries of pairs, each finger of said pair being connected to a separatebar;

the fingers of one of said bars having a common radius of curvatureunlike the common radius of curvature of the fingers of the other ofsaid bars, said fingers all terminating in tip ends of angular formationlying in a common plane;

each pair of adjacent fingers from said respective bars being infrictional contact in said common plane with the cylindrical peripheryof one of said rotatable tumblers; t

whereby a multiple switch circuit may be provided by the use of only twointegral conductive elements and whereby stresses applied to saidelongated spring fingers by the rotation of said tumblers will beabsorbed by the resiliency of the spring fingers within the lengththereof with minimal transfer to the bus 15 bars and to their bondingcomponents. 2. A structure as set forth in claim 1, wherein said springcontact fingers are all substantially tangential to the peripheralsurfaces ott said tumblers.

References Cited by the Examiner UNITED STATES PATENTS Wise 200-43Lawrence ZOO-43 Tulloch 200-45 G'iffin 200-45 Augustine 200-43 Goral20045 Davidson 20045 BERNARD A. GILHEANY, Primary Examiner.

ROBERT K. SCHAEFER, Examiner.

1. IN A PERMUTATION SWITCH INCLUDING A HOLLOW CYLINDRICAL CASING CLOSEDAT BOTH OF ITS END HAVING A PLURALITY OF CYLINDRICAL TUMBLERS ROTATABLYMOUNTED THEREIN WHICH HAVE CONDUCTING AND NON-CONDUCTING SURFACEPORTIONS, ELECTRICAL CONDUCTORS EXTENDING TO THE INTERIOR OF THEHOUSING, AND A SEMI-CYLINDRICAL MOUNTING PLATE SUPPORTED WITHIN THECASING AND HAVING A RELATIVELY THICK CHORDAL INNER FACE, THE IMPROVEMENTCOMPRISING. A PAIR OF BUS BARS OF FLAT FORMATION THROUGHOUT THEIR LENGTHSECURED TO AND SPACED FROM EACH OTHER BY A DIELECTRIC BONDING MATERIALTHROUGHOUT THE MAJOR PROTION OF THEIR LENGTH AND DIVIDED OUTWARDLYBEYOND ONE END OF SAID BOND INTO TWO CONDUCTIVE TERMINALS ELECTRICALLYCONNECTED TO SAID CONDUCTORS; BOTH BUS BARS BEING BONDED AS A UNITTHROUGHOUT THEIR SAID MAJOR PORTION TO SAID CHORDAL INNER FACE OF SAIDMOUNTING PLATE; EACH OF SAID BUS BARS HAVING LATERALLY, OUTWARDLYEXTENDING, SPACED APART INTEGRAL SPRING CONTACT FINGERS CURVEDDOWNWARDLY, THE FINGERS OF ONE OF SAID BARS STRADDLING THOSE OF THEOTHER OF SAID BARS TO PROVIDE A SERIES OF PAIRS, EACH FINGER OF SAIDPAIR BEING CONNECTED TO A SEPARATE BAR; THE FINGERS OF ONE OF SAID BARSHAVING A COMMON RADIUS OF CURVATURE UNLIKE THE COMMON RADIUS OFCURVATURE OF THE FINGERS OF THE OTHER OF SAID BARS, SAID FINGERS ALLTERMINATING IN TIP ENDS OF ANGULAR FORMATION LYING IN A COMMON PLANE;EACH PAIR OF ADJACENT FINGERS FROM SAID RESPECTIVE BARS BEING INFRICTIONAL CONTACT IN SAID COMMON PLANE WITH THE CYLINDRICAL PERIPHERYOF ONE OF SAID ROTATABLE TUMBLERS; WHEREBY A MULTIPLE SWITCH CIRCUIT MAYBE PROVIDED BY THE USE OF ONLY TWO INTEGRAL CONDUCTIVE ELEMENTS ANDWHEREBY STRESSES APPLIED TO SAID ELONGATED SPRING FINGERS BY THEROTATION OF SAID TUMBLERS WILL BE ABSORBED BY THE RESILIENCY OF THESPRING FINGERS WITHIN THE LENGTH THEREOF WITH MINIMAL TRANSFER TO THEBUS BARS AND TO OTHER BONDING COMPONENTS.